Missed days
What I'd tell you: You will miss days. Work runs long. A kid gets sick. That's life, and you'll be okay. One missed day doesn't erase a training block.
But don't miss on purpose. There's a difference between life taking a day and you handing it over.
What I actually do: My weeks swing. I've had 60-mile weeks next to zero-mile weeks. That's not a strategy. It's what happens when work and family and running share the same seven days.
The thing I try to get right is the comeback. After a zero week, no hero rebound. I don't try to make the miles back. I go back to the plan for the week I'm actually in.
On Oct 19–25 the quality session was planned for Thursday: cruise intervals. Thursday turned into 3.56 miles squeezed between client calls. The speed moved to Friday. It changed shape too: 1 mile at 5:50, a mile easy, then 1 mile at 6:30 up a dirt hill. Not the workout on paper. But it got run.
On Oct 26–Nov 1 Wednesday was busy, so the quality moved to Thursday. Both weeks, it landed a day late. A call cut the warm-up short. I finished it on a treadmill: 1 mile at 6:00, half a mile at 6:00, then 4×1:00 at 6:00.
Moving a workout a day is fine. Dropping it every time something comes up isn't.